Genus: Highly flattened; pellicle firm; body form constant (Kudo, 1966).
Chloroplasts small, discoid, pyrenoids usually absent; most species flat and leaf-shaped;
often with ridges or fins running helically or longitudinally (Illustrated Guide, 1985).
Species: Cell body 37-68 μm long, 25-45 μm wide, dorsally broad ovoidal, cauda relatively long and curved, striae straight, a longitudinal prominent ridge at the center which makes frontal view triangular; a locomotive flagellum nearly the same as the cell body in length; paramylon bodies large disc-shaped, 1-2 in number (An Illustrated Guide to Freshwater Zooplankton in Japan, 2000). |
31 μm
63 μm
94 μm; x 640
Phacus triqueter (Ehrenberg) Dujardin or P. curvicauda ?,
cell body 42 μm long, 32 μm wide, L/W=,
x 640, Kareki-numa marsh, Nikko city (formerly Fujiwara town), Tochigi Pref., Japan, August 2, 2008, collected by Eizaburo Tsukii, photo by Y. Tsukii
31 μm
63 μm
94 μm; x 640
